A medium made by mounting an electronic circuit on an optical disk (hereinafter, this is called an intelligent disk (ID)) is known. In this case, in regard to the information transfer between the electronic circuit and an external apparatus, it is common to provide a connector nearby a rotary shaft of the disk or to connect via radio communication, optical communication, and the like, in consideration of a rotary disk.
Nevertheless, as an electronic circuit block of an ID has high-performance and the construction of the ID subjectively controlling an external apparatus becomes widespread, quantity and speed of the information transfer between the electronic circuit block and external apparatus restricts the performance of the entire system.